package com.nmc.service.dao.impl;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.Collection;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Map;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.hibernate.SessionFactory;
import org.springframework.orm.ObjectRetrievalFailureException;
import org.springframework.orm.hibernate3.HibernateTemplate;
import org.springframework.orm.hibernate3.support.HibernateDaoSupport;

import com.nmc.service.dao.GenericDao;
import com.nmc.service.model.User;

/**
 * This class serves as the Base class for all other DAOs - namely to hold
 * common CRUD methods that they might all use. You should only need to extend
 * this class when your require custom CRUD logic.
 *
 * @author <a href="mailto:udaykumarchinna@gmail.com">uday kumar</a>
 * @param <T> a type variable
 * @param <PK> the primary key for that type
 */
public class GenericDaoImpl<T, PK extends Serializable> extends HibernateDaoSupport implements GenericDao<T, PK> {
    public GenericDaoImpl() {
		super();
		// TODO Auto-generated constructor stub
	}

	/**
     * Log variable for all child classes. Uses LogFactory.getLog(getClass()) from Commons Logging
     */
    protected final Log log = LogFactory.getLog(getClass());
    private Class<T> persistentClass;
    private HibernateTemplate hibernateTemplate;
    private SessionFactory sessionFactory;

    /**
     * Constructor that takes in a class to see which type of entity to persist.
     * Use this constructor when subclassing.
     *
     * @param persistentClass the class type you'd like to persist
     */
    public GenericDaoImpl(final Class<T> persistentClass) {
        this.persistentClass = persistentClass;
    }

    /**
     * Constructor that takes in a class and sessionFactory for easy creation of DAO.
     *
     * @param persistentClass the class type you'd like to persist
     * @param sessionFactory  the pre-configured Hibernate SessionFactory
     */
    public GenericDaoImpl(final Class<T> persistentClass, SessionFactory sessionFactory) {
        this.persistentClass = persistentClass;
        this.sessionFactory = sessionFactory;
        this.hibernateTemplate = getHibernateTemplate();
    }

//    public HibernateTemplate getHibernateTemplate() {
//        return this.hibernateTemplate;
//    }
//
//    public SessionFactory getSessionFactory() {
//        return this.sessionFactory;
//    }
//
//    
//    public void setSessionFactory(SessionFactory sessionFactory) {
//        this.sessionFactory = sessionFactory;
//        this.hibernateTemplate = new HibernateTemplate(sessionFactory);
//    }

    /**
     * {@inheritDoc}
     */
    @SuppressWarnings("unchecked")
    public List<T> getAll() {
        return getHibernateTemplate().loadAll(this.persistentClass);
    }

    /**
     * {@inheritDoc}
     */
    @SuppressWarnings("unchecked")
    public List<T> getAllDistinct() {
        Collection result = new LinkedHashSet(getAll());
        return new ArrayList(result);
    }

    /**
     * {@inheritDoc}
     */
    @SuppressWarnings("unchecked")
    public T get(PK id) {
        T entity = (T) getHibernateTemplate().get(this.persistentClass, id);

        if (entity == null) {
            log.warn("Uh oh, '" + this.persistentClass + "' object with id '" + id + "' not found...");
            throw new ObjectRetrievalFailureException(this.persistentClass, id);
        }

        return entity;
    }

    /**
     * {@inheritDoc}
     */
    @SuppressWarnings("unchecked")
    public boolean exists(PK id) {
        T entity = (T) getHibernateTemplate().get(this.persistentClass, id);
        return entity != null;
    }

    /**
     * {@inheritDoc}
     */
    @SuppressWarnings("unchecked")
    public T save(T object) {
        return (T) getHibernateTemplate().merge(object);
    }

    /**
     * {@inheritDoc}
     */
    public void remove(PK id) {
        getHibernateTemplate().delete(this.get(id));
    }

    /**
     * {@inheritDoc}
     */
    @SuppressWarnings("unchecked")
    public List<T> findByNamedQuery(String queryName, Map<String, Object> queryParams) {
        String[] params = new String[queryParams.size()];
        Object[] values = new Object[queryParams.size()];
        
        int index = 0;
        for (String s : queryParams.keySet()) {
            params[index] = s;
            values[index++] = queryParams.get(s);
        }

        return getHibernateTemplate().findByNamedQueryAndNamedParam(queryName, params, values);
    }

	public List<User> searchUsers(String searchStr) {
		// TODO Auto-generated method stub
		return null;
	}
}
